Opaque materials for x-ray and radium work or the like



Dec. 19, 1939.

E. R. DILLEHAY ET! AL 2,183,790

- OPAQUE MATERIAL FOR X-RAY AND RADIUM WORK OR THE LIKE Filed March 21,1935 INVENTORS. [ow/ma R D/LLEHA Y 62-0965 M MY'Z'aR/Es.

ATTORNEYS,

Patented Dec. 19, 1939 UNITED STATE$ rarest orrics OPAQUE MATERIALS FORX-RAY AND RA- DIUM WOKK OR THE LIKE Application March 21, 1935, SerialNo. 12,272

2 Claims.

The primary object of our invention is to provide an isolating structurewhich can be used for X-ray work, or the like. It has long been realizedthat radium and X-rays have a deleterious efiect upon living organisms,as well as sensitized material such as films. It is usual, for example,to line cabinets in which X-ray apparatus is contained, with lead as amedium substantially opaque to the rays, and to leave in D: a desiredposition a window for the passage of such rays. It has also been foundthat where X- ray work is being carried on in a room, deleteriouseffects may be experienced by persons in adjacent rooms, andconsiderable pressure from various 5 sources has been brought uponpersons working with X-rays to isolate in some way the rooms in whichthe work is being carried on. It is usual to line these rooms with lead,but this gives to the room an unsightly appearance. An object of ourinvention, therefore, is to provide an isolating medium which isattractive in appearance, and which may be employed in such a way as notto make the room appear different in its appointments from ordinaryrooms, and so as not, for example, to emphasize the dangerous featuresof the work being carried on in the room. It is an object of ourinvention to provide a material which will have adequate isolatingefiect, which may be applied in such a way as to produce completeisolation, and which will be relatively inexpensive and capable ofimparting to the room various decorative effects.

These and other objects of our invention which will be set forthhereinafter, or will be apparent to one skilled in the art upon readingthese specific-ations, we accomplish by that certain construction andarrangement of parts and in that material of which we shall hereinafterset forth an exemplary embodiment.

m Reference may be made to the drawing,

wherein:

Figure 1 shows in cross section an embodiment of our invention in thebest form known to us, and

45 Fig. 2 shows a section of a wall paneled with our material.

In the practice of our invention, we take a sheet of lead or othersuitable isolating material of the required thickness having in regardthe particular form of the rays which are to be cut ofi, and weassociate this with a panel of decorative substance which need not havethe isolating effect referred to. Preferably the two panels will befastened together so that they may be handled, 55 sold, shipped andinstalled as a unit. In the particular embodiment of our invention wejoin to a sheet of lead a panel of moulded or laminated compositionhaving the desired decorative effect. The last mentioned panel mayadvantageously be made of moulded or laminated con- 5 densation resin,and may be given any of the decorative effects of which said resins orresinous compositions are capable.

The decorative panel may be made in solid colors or not, as desired, andmay have other decorative effects, as we shall hereinafter describe.

It is possible, for example, by employing either a moulding compositionwhich is light or white in color, or a laminated structure which willgive a similar effect, to produce wall coverings which 1-5 have theappearance of white or light colored til-e, and the suggestion ofsanitation which such materials convey. Moulded products of thischaracter can be made with a high surface lustre and are washable, andnot subject to attack by acids or alkalies, for which reason they areactually sanitary and veryreadily kept clean. For most uses, as, forexample, in a doctors oflice, the tendency of present day decoration isusually in other directions than that of a tiled effect, and

consequently in commercial practice we manufacture most of our panelswith a decorative effect having the appearance of wood graining.

The decorative panel of our structure is most conveniently made by alaminating procedure, as is well known in the art. Sheets of paper orcloth are passed through a bath or otherwise saturated with the desiredresin in an uncured state, and then are laminated in a press, and curedunder a high degree of pressure and heat, so as to complete thepolymerization of the resin and to give a product which is hard,insoluble and infusible.

In the manufacture of wood grained effects, as is also known in the art,it is usual to employ as the top or surface lamination a layer of pap-eror 40 other web which, by printing or otherwise, has been given asurface marking representative of the grain of a chosen type of wood,such, for example, as oak, walnut, mahogany, or the like, and then toemploy this with a resin which will be transparent in thin films, andwhich may have a coloring appropriate to the particular type of woodwhich it is intended to imitate. In the curing operation, the surfacewhich is to be exposed is usually placed against a highly polished sheetof metal which gives it the final polish and lustre.

Finished panels of this type may be associated with panels of lead, orthe like, in any way desired. They may, for example, merely be packagedand shipped together, but it is preferable to fashion them in a unit byany one of a number of methods. It is possible, for example, to fasten asheet of lead to a panel of resinous material by means of rivets, whichrivets will preferably be of a material such as lead which is imperviousto X-rays. It is likewise possible to form a lead sheet with teeth orundercut portions and to cure a moulded panel thereagainst in such a waythat a portion of the moulding composition or of the panel is caught andheld by or beneath the teeth so as to give a physical bond. We prefer,however, to form the lead and the decorative panel into an inseparableunit without the use of any of these expedients, and We have found thatthis may be done by any of the following methods:

Example No. 1.-Since lead does not appear to possess a strong adhesionto condensation products, it is preferable to coat the lead after it hasbeen cleaned as by wire brushing, an acid treatment, or the like, withan adhesion promoting metal. There are a number of metals, such, forexample, as zinc, which will serve in this connection; but we havesecured our best results by coating the lead with copper, or with analloy containing copper, such as brass. This may and preferably will bedone electrolytically. Between the coated lead and either a raw orpre-cured panel containing condensation resin made as hereinabovedescribed, we place a thin calendered sheet of rubber stock, or we coatboth the lead and the resinous panel with a rubber cement, or withrubber latex, preferably containing curing agents, such as sulphur andaccelerators. If latex or rubber cement is employed, the solvent in thefirst case or the dispersing medium, such as Water, in the second, areallowed to dry out of the surfaces of the coated stock, and the resinouspanel is then superposed upon the lead sheet. The combined article, or anumber of them, are placed in the ordinary press and given either thenormal cure for condensation resins of the type employed, or a heat andpressure treatment sufficient to vulcanize the rubber. Where theresinous panel is of uncured stock, the normal curing treatment will besufficient to effect a vulcanization of the rubber, and as a consequenceit is somewhat cheaper to employ uncured resinous panels or to build upthe panel on the surface of the lead, after a manner which will be clearfrom the foregoing.

The combined article is an integral article, one surface of which is oflead, and the other surface of which is of moulded resinous compound,the two being joined together with a good bond and being substantiallyinseparable. We have not found that differences in temperatureordinarily to be encountered by such products in use have any effect onthe compound, nor have we noted in our products in use any tendencytoward warpage.

Example No. 2.A sheet of lead, or the like, of required thickness, maybe cleaned and coated with a Bakelite varnish or cement. Preferably,though not necessarily, the lead will have been plated as describedabove. A panel of the resinous composition, either in a cured or uncuredstage, will also be coated with a Bakelite or resinous cement. It willbe understood that the resinous cement referred to is a condensationresin in an incompletely cured condition, softened with an appropriatesolvent. The coated panels are superposed, and one or more of theassemblies described are placed in a press and treated under heat andpressure sufficient at least for curing the cement. Where the resinouspanel has been built up upon the lead, or where an uncured panel isemployed, the treatment will, of course, be suflicient to cure theresinous compound.

Example N0. 3.-The cleaned lead or other isolating panel, treated or notwith adhesion promoting substance, is coated with a nitro-cellulose orcellulose acetate base cement, or other cellulosic cementitioussubstance, and the resinous panel is likewise so coated. The coatingsmay be allowed partially to dry, but not so as to lose their entireadhesiveness. Then the panels are pressed together and allowed to becomethoroughly dry, with or without the use of heat. This procedure likewisehas been found to give a good bond.

In the drawing:

Figure 1 is a sectional view of an exemplary article made in accordancewith our invention, in which 4 indicates the resinous panel; 2 is apanel of isolating substance such as lead, and 3 an intermediate layerof bonding material.

In Fig. 2 we have shown a section of wall paneled With this material,and an exemplary joining structure. Adjacent sheets of our material areindicated respectively at 4, 5, 6 and 1. Overlying joint seal strips areindicated at 8, 9, l0 and II. These strips may be cemented, or otherwiseheld in place, or they may be held in place by metallic fasteningdevices indicated at l2. These may be in the nature of screws, such asscrew members with self-cutting threads, and they may fasten the panelstrips to the body panels without complete penetration through theisolating layer of the body panels. Where complete penetration isdesirable or necessary, the fastening means may be made of, or maycomprise the desired isolating substance, such as lead. If the panelsare relatively small, it may not be necessary to fasten the joiningstrips otherwise than at their ends. We have shown their ends beveled,as at it, and meeting over the point of juncture of the panels. eredscrew or bolt l4 may be employed simultaneously to hold the mainisolating panels and the joining strips as shown.

It will be understood that our materials are not restricted in their useto the lining of the walls of X-ray rooms or rooms in which X-ray andradium work is carried on. Our materials have utility in theconstruction of cabinets or At this point a lead coviii housings forX-ray apparatus, in the construction of shields for the protection ofthe o-perators body, which shields or screens may be movable or not asdesired, also in the construction of boxes or containers for radium, orfor sensitized materials stored adjacent to sources of destructiveradiation, or for any other isolative uses. Decorative panels may, ofcourse, be placed upon both sides of the isolative panel if desired.

Ordinarily, in the manufacture of our materials we employ commercialsheet lead, or commercial sheets of other isolative materials. The wordssheet and layer in the appended claims are not intended as implying alimitation to commercially formed sheets. For example, a layer of leadmay be formed by spraying the metal upon a suitable base, which may bethe decorative panel, if desired, preferably coated with the selectedadhesive substance. The selection of a suitable thickness of the layerof isolative substance per se, for any particular isolative use, will bewithin the skill of the worker in the art in accordance with knownprinciples.

Modifications may be made in our invention without departing from thespirit thereof.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent, is:

1. In combination, a layer of lead and a decorative panel ofcondensation resinous composition, said lead being coated with anadhesion promoting metal and bonded to said panel by a bondingsubstance.

2. A process of manufacturing isolating panels, which comprises cleaninga sheet of lead, coating said lead with an adhesion promoting metal, andwith an adhesive substance, forming a resinous panel and coating saidpanel with an adhesive substance, afterward superposing said sheet andsaid panel and pressing and curing the combined structure.

EDWARD R. DILLEIHAY. GEORGE M. MCFEDRIES.

